The present invention is directed to improving devices for protecting the valve, gauge, and regulator assembly of pressurized cylinders.
Gas cylinders typically comprise strong steel vessels of cylindrical shape in which gases are stored under high pressure. Provided at one end of the gas cylinder is a necked down portion having a cylinder valve including a valve outlet fitting to which a pressure regulator or the like can be connected. A hand-wheel for operating the valve is typically permanently attached to the valve stem.
Threads on the necked down portion of the cylinder provide a means whereby a heavy steel cap is screwed over the valve to protect it from injury during shipment. If the cylinder valve should ever be broken off, the very high pressure of the gas in the cylinder, under escaping tends to give the cylinder rocket propulsion. Because of this danger, it is essential that the cap be in place during shipment and handling of the gas cylinder.
OSHA's construction standard for storing compressed gas cylinders are addressed in § 1926.350(a), which states in part:
OSHA standards § 1926.350 Gas welding and cutting.                (a) Transporting, moving, and storing compressed gas cylinders.                    (1) Valve protection caps shall be in place and secured.            (6) Unless cylinders are firmly secured on a special carrier intended for this purpose, regulators shall be removed and valve protection caps put in place before cylinders are moved.                        
Gases such as chlorine are customarily shipped and stored prior to use in cylindrical tanks. These tanks have a gas release valve at their top through which the gas is pumped to fill the tank, and through which the gas is permitted to escape when it is desired to use the gas. A cap is generally provided to protect the valve from damage when the tank is shipped, stored or otherwise not in use. This cap completely covers the valve and is seated on the tank over the valve by twisting its threaded lower inner edge onto the threaded nub of a cap plate which is attached to the tank with its threaded nub surrounding and concentric with the base of the valve.
High-pressure gas cylinders hold industrial and welding gases for example carbon dioxide, oxygen, propane, nitrogen, argon, Freon, helium, and hydrogen. The gas pressures can range from 2,000 to 3,000 psi. Upon delivery of a high-pressure gas cylinder to its ultimate destination be it a plant, factory, shop, or hospital, it is installed for use with its shut-off valve connected to a regulator which has its own monitoring pressure gauge. In such an installation the valve is exposed to damage and tampering. High-pressure gas cylinders have sufficient propulsive force to drive through a concrete wall in the event the shut-off valve is broken off or damaged. What is needed is a secure, efficient way of installing and removing a safety cap to protect the valve.